No BEags, simply a what if.
We knew the F2 was coming in but the capability could have been developed in the airframe as the role shifted to the Tornado. The plot was clearly to field a superb interceptor in the guise of the F2; its short comings were, apparently, not obvious then. In other words my suggestion is also made with hindsight.
As for the Lightning it was an interceptor of a different ilk. The F3/6 could hold a ground alert against a free-fall bomber whereas the F3 really needed to intercept at long range against a missile carrier. The Vulcan could not have replaced a Lightning in th eformer role but could have been very effective in the latter.
It could also have been a fine airframe for Dale Brown to get his hands on - a load of Paveway, MRAAM, SRAAM and ARM, coul dhave completed the suite.